FYI in our district, all volunteers need to be fingerprinted and approved. Having another adult in the classroom requires another set of behavior expectations. I would wait until you know when he is coming to mention that he would be part of your classroom.
For the ppt. I would focus and your educational background: high school, extra curricular activities, summer jobs, college etc.. and then mention family and pets
I would switch the worksheet to focus on getting to know the kids. There are some very sneaky parents that will try to find out info about you (though Facebook and social media) and I keep my personal life private.